A remote display protocol is a protocol that can be used to allow the user interface of an application or desktop hosted on a server to be displayed on a client device. Similarly, a remote display protocol can be used to redirect user input on the client device to the server where the application or desktop is hosted thereby allowing the user of the client device to interact with the application or desktop.
One feature that is often provided with a remote display protocol is host-side rendering. Host-side rendering (also known as redirection) refers to an optimization technique where the server (i.e., the host of the application or desktop whose interface is being remoted) renders the content to be displayed (e.g., into bitmaps), encodes this content, and then transmits the encoded content to the client. The client can then decode the content and display it. Common examples of remote display protocols that provide host-side rendering include Microsoft's RemoteFX, Teradici's PC over IP, and Citrix Systems' HDX.
Host-side rendering can be employed with any type of client. However, it is especially beneficial with thin clients. For example, host-side rendering enables support for all graphics types by sending highly compressed bitmap images to the client in an adaptive manner. This also allows the applications to run at full speed on the server by taking advantage of the GPU and the CPU thereby providing an experience that is similar to a locally executed application or desktop.